Frequency multiplier



Patented Feb. 4, 1930 y UNITED STATES PATENT OFFICE GEORG Von ARGO, OFBERLIN, GERMAN Y, ASSIGNOB- TO GESELLSCHAFT FU'R DRAHTLOSE TELEGRAPHIEM. B. H.,

OF BERLIN, GERMANY FREQUENGY MULTIPLIER In the known methods forincreasing the frequency of any fundamental period by means of statictransformers a large number of frequency transformers connected incascade was used, each step of thearrangement only doubling or triplingthe frequency. This method has, however, a poor efficiency because everystep of the cascade causes a loss of energy. This loss increases nearlyin proportion to the frequency which, of course, rises in geometricalprogression.

This method had, therefore, low efficiency and thearrangementwascomplicated and expensive. Accordingly this method was replaced by thatof increasing the frequency by means of a single transformer. By thismethodit was possible to attain ratios of transformation as high as1:27. In using one single transformer a very simple arrangement wasobtained, but an analysis of the radiated oscillation showed that thisoscillation contained very many adjacent harmonics. These harmonics of atransmitting station greatly disturb those neighboring receivingstations which are tuned to a wavelength which is by chance inaccordance with one of these harmonics.

The present invention relates to an arrangement for frequently increaseby which a final frequency is generated which contains only very fewdisturbing harmonics.

' According to the invention the frequency increase, particularly thatof a high multiple of the fundamental frequency is always car ried outby means of two transformers, the first fitted up for a great frequencyincrease and the second only for a small frequency increase, forinstance doubling or tripling the input frequency.

It is attained by reason that the disturbing harmonics according to theinvention greatly differ from the radiated desired final oscillation inspite of a very high transformation. By means of traps and filters, wellknown in the art these greatly differing harmonics can easily beeliminated.

The single figure shows diagrammatically an embodiment of my inven lgn.

In said figure, the high frequency generator is shown coupled to thefirst frequency 731,225, and in Germany August 17, 1928.

changer circuit which in turn leads to the second frequency changer andthen to'the utilizing circuit.

An example will serve to explain this invention. Assume the fundamentalfrequency to be 10,000 and it is desired to increase it 27 times. Thefirst transformation will then increase the fundamental frequency 9times, that is, to 90,000 and the second transformation increases thisfrequency 3 times, that is, to 270,000. Thus the useful frequency is270,000 while the next disturbing waves have the frequencies 450,000 and90,000, assuming thatthe frequency multipliers used generate only oddharmonics. Many of the well known frequency changers can be made togenerateonly odd harmonics. These harmonics greatly differing from theuseful frequency have but small energy and can if necessary be easilyeliminated by means of any well known filtering circuits, as pointed outabove.

The above described arrangement is specially simplified if, as'in theabove example, the second transformation increases the frequency 3 timesand if the first transformation is so chosen that it increases thefundamental frequency by an odd but greater multiple. In this case thedirect current magnetization absolutely necessary for the even multiplescan be left out and an extraordinarily simple and good arrangement isobtained.

Having described my invention, I claim :J

1. In a high frequency multiplication system of the character describedfor changing a fundamental frequency into a higher frequency comprisingin combination an iron cored frequency multiplication transformer havingits input circuit fed by current of said fundamental frequency, asecond. frequency multiplication transformer connected in cascade withsaid first frequency transformer and having a multiplication ratiorelativel small with respect to that of the first frequency transformer.

2. In a high frequency multiplication system of the character describedfor changing a fundamental frequency into another higher cored frequenctransformer having its input circuit fe by said fundamental frequency, asecond frequency transformer having a multiplication ratio relativelysmall with respect to that of the first frequency transformer and meansfor coupling the output circuit ofthe first transformer with said inputcircuit of said second transformer.

3. A device for greatly increasing the frequency of oscillation in anelectrical system by means of static transformers which com prises apair of static transformers, the second thereof bein ada ted to increasethe outgut frequency 0 the rst three times and the rst thereof beingadapted to increase the fundamental frequency by an odd but greatermultiple, whereby it is unnecessary to magnetize the. cores of thetransformers by direct current.

4. A device for quency of electrical oscillations by means of statictransformers whichcomp'rises means including a first static transformeradapted to increase the fundamental frequency by an odd multiple and asecond static transformer adapted to increase the frequency produced bysaid first static transformer. by a multiple less than the said multipleincrease in said first transformation.

' 5; A. device for greatly increasing the frequency of electricaloscillations .by means of 7 static transformers which comprises meansincluding .a first static transformer adapted to increase thefundamental frequency nine times and a second statictransformer ada tedto increase the frequency produced by said first static transformerthree times.

GEORG VON ARGO.

greatly increasing the fre-

